| Message ID | 1474663484-23245-1-git-send-email-bo.li.liu@oracle.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Fri, Sep 23, 2016 at 01:44:44PM -0700, Liu Bo wrote: > @@ -3732,15 +3734,21 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb, > if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID) > bio_flags = EXTENT_BIO_TREE_LOG; > > - /* set btree node beyond nritems with 0 to avoid stale content */ > + /* set btree blocks beyond nritems with 0 to avoid stale content. */ > + nritems = btrfs_header_nritems(eb); > if (btrfs_header_level(eb) > 0) { > - u32 nritems; > - unsigned long end; > - > - nritems = btrfs_header_nritems(eb); > end = btrfs_node_key_ptr_offset(nritems); > > memset_extent_buffer(eb, 0, end, eb->len - end); > + } else { > + /* > + * leaf: > + * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0 > + */ > + start = btrfs_item_nr_offset(nritems); So, AFAICS this also works for empty root nodes (nritems == 0). It's hidden in leaf_data_end that actually looks at nritems and decides. Reviewed-by: David Sterba <dsterba@suse.com> > + end = btrfs_leaf_data(eb) + > + leaf_data_end(fs_info->tree_root, eb); > + memset_extent_buffer(eb, 0, start, end - start); -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Sep 26, 2016 at 06:54:44PM +0200, David Sterba wrote: > On Fri, Sep 23, 2016 at 01:44:44PM -0700, Liu Bo wrote: > > @@ -3732,15 +3734,21 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb, > > if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID) > > bio_flags = EXTENT_BIO_TREE_LOG; > > > > - /* set btree node beyond nritems with 0 to avoid stale content */ > > + /* set btree blocks beyond nritems with 0 to avoid stale content. */ > > + nritems = btrfs_header_nritems(eb); > > if (btrfs_header_level(eb) > 0) { > > - u32 nritems; > > - unsigned long end; > > - > > - nritems = btrfs_header_nritems(eb); > > end = btrfs_node_key_ptr_offset(nritems); > > > > memset_extent_buffer(eb, 0, end, eb->len - end); > > + } else { > > + /* > > + * leaf: > > + * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0 > > + */ > > + start = btrfs_item_nr_offset(nritems); > > So, AFAICS this also works for empty root nodes (nritems == 0). It's > hidden in leaf_data_end that actually looks at nritems and decides. > > Reviewed-by: David Sterba <dsterba@suse.com> Yeah, you're right, case (nritems == 0) has already been taken care in this patch. Thanks a lot for reviewing it. Thanks, -liubo > > > + end = btrfs_leaf_data(eb) + > > + leaf_data_end(fs_info->tree_root, eb); > > + memset_extent_buffer(eb, 0, start, end - start); > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index d1c56c9..f138cf7 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1729,20 +1729,6 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans, return err; } -/* - * The leaf data grows from end-to-front in the node. - * this returns the address of the start of the last item, - * which is the stop of the leaf data stack - */ -static inline unsigned int leaf_data_end(struct btrfs_root *root, - struct extent_buffer *leaf) -{ - u32 nr = btrfs_header_nritems(leaf); - if (nr == 0) - return BTRFS_LEAF_DATA_SIZE(root); - return btrfs_item_offset_nr(leaf, nr - 1); -} - /* * search for key in the extent_buffer. The items start at offset p, diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 33fe035..67d71c0 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -2293,6 +2293,21 @@ static inline unsigned long btrfs_leaf_data(struct extent_buffer *l) return offsetof(struct btrfs_leaf, items); } +/* + * The leaf data grows from end-to-front in the node. + * this returns the address of the start of the last item, + * which is the stop of the leaf data stack + */ +static inline unsigned int leaf_data_end(struct btrfs_root *root, + struct extent_buffer *leaf) +{ + u32 nr = btrfs_header_nritems(leaf); + + if (nr == 0) + return BTRFS_LEAF_DATA_SIZE(root); + return btrfs_item_offset_nr(leaf, nr - 1); +} + /* struct btrfs_file_extent_item */ BTRFS_SETGET_FUNCS(file_extent_type, struct btrfs_file_extent_item, type, 8); BTRFS_SETGET_STACK_FUNCS(stack_file_extent_disk_bytenr, diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 176f883..04a8e2a 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3721,8 +3721,10 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb, struct block_device *bdev = fs_info->fs_devices->latest_bdev; struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree; u64 offset = eb->start; + u32 nritems; unsigned long i, num_pages; unsigned long bio_flags = 0; + unsigned long start, end; int write_flags = (epd->sync_io ? WRITE_SYNC : 0) | REQ_META; int ret = 0; @@ -3732,15 +3734,21 @@ static noinline_for_stack int write_one_eb(struct extent_buffer *eb, if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID) bio_flags = EXTENT_BIO_TREE_LOG; - /* set btree node beyond nritems with 0 to avoid stale content */ + /* set btree blocks beyond nritems with 0 to avoid stale content. */ + nritems = btrfs_header_nritems(eb); if (btrfs_header_level(eb) > 0) { - u32 nritems; - unsigned long end; - - nritems = btrfs_header_nritems(eb); end = btrfs_node_key_ptr_offset(nritems); memset_extent_buffer(eb, 0, end, eb->len - end); + } else { + /* + * leaf: + * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0 + */ + start = btrfs_item_nr_offset(nritems); + end = btrfs_leaf_data(eb) + + leaf_data_end(fs_info->tree_root, eb); + memset_extent_buffer(eb, 0, start, end - start); } for (i = 0; i < num_pages; i++) {
This is an additional patch to "Btrfs: memset to avoid stale content in btree node block". This uses memset to initialize the unused space in a leaf to avoid potential stale content, which may be incurred by pushing items between sibling leaves. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> --- Tested with fstests '-g quick': no related panic or warning. fs/btrfs/ctree.c | 14 -------------- fs/btrfs/ctree.h | 15 +++++++++++++++ fs/btrfs/extent_io.c | 18 +++++++++++++----- 3 files changed, 28 insertions(+), 19 deletions(-)